The dynamic range of a digital image device, such as a digital camera, is the ratio between the largest amount of light that the device can capture without saturation, to the lowest amount of light the device can accurately measure and distinguish from intrinsic image noise (electrical, thermal, etc.). Most off-the-shelf digital cameras are able to capture only a small portion of the natural illumination range of a real-world scene.
Typical digital cameras, based on CMOS (complementary metal-oxide-silicon) or CCD (charge coupled device) technologies, capture images as low dynamic range (LDR) images. LDR images often means that the dynamic range of colors of a captured image is limited or clipped. An example of such resulting images may include areas that are too dark being producing a signal which is below the intrinsic noise level of the electronic sensor and areas that are determined to be too bright being clipped to white (sometimes called saturation).
High Dynamic Range (HDR) image solutions seek to increase the illumination dynamic range that is captured, to provide a fuller range of image colors. For example, darker images might appear in various shades of gray to provide increased image details that might be present in a scene's shadow region. HDR solutions then seek to preserve details in an image that may otherwise be lost due to limiting contrast ratios. Thus, it is with respect to these considerations and others that the present invention has been made.